The ballistic armoring field is relatively small, made up of small companies - and everyone wants your business. You can buy from catalogs, factory direct or distributors. But most importantly you need a professional to guide you through the minefields.
Initially, adding bullet resistant armoring may seem simple and there are those who have tried to make it appear no different from other building materials. In actuality, the bullet resistant field is very complex. This is why reputable companies use Underwriters Laboratories Standard 752 (UL-752) as their guide. They understand the difference between LISTED and MEETS and don't use other testing facilities as being comparable to UL. It is also why they don't say bullet proof.